US Patent 7246691 Fluid friction clutch for a motor vehicle fan

A fluid friction clutch for a motor vehicle fan comprises at least one rotatably mounted shaft, a drive element firmly mounted on the shaft so as to rotate with it and a driven element rotatably mounted about the axis of the shaft. The drive element and driven element form a coupling region, which accommodates a viscous fluid. A fan member is connected to the outer region of the driven element by means of at least one partially plastic or plastic-encapsulated fixing ring arranged concentrically with respect to the axis of rotation.